Improved rotary cultivator



H. M.JOH NSON.

Rotary Cultivator.

Patented June 27, 1854.

UNITED STATES PATENT O FICE.

H. M. JOHNSON, OF GARLISLE, PENNSYLVANIA.

IM PROVED ROTARY CULTIVATO R.

Specification forming part of Letters Patent No. 11,162, dated June 27, 1854.

To all whom it may concern:

Be it known that I, H. M. JOHNSON, of (Jarlisle, in the county of Cumberland, the State of Pennsylvania, have invented'a new and useful Machine for Cultivating the Soil; and I do hereby declare thatthefollowingis a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making part of this specification.

Figure 1 is a perspective view of the essential parts of the machine.

The frame A B supports three sets of colter or toothed wheels, as herein further described. The first set, a a a a, are merely circular rotary colters. They are made of plow'steel or other substantial metal as thin as is consistent with due strength. They are beveled to an edge, and at the height of the bevel are slightly thicker than in the interior part in order to lessen the friction. They are placed at a suitable distance apart, which might vary in different soils, say, from two to three inches, or in light soils even more. They serve to cut through the turf and soil, together with roots and other lightobstructions, toa proper depth. The second and third sets, I) b and c, are so. placed as to come alternately directly in the center of the sections made by the first set. They consist of, first, a colter precisely like those of the first set, a a; second, the edge is set with wings or knives projecting laterally, w w w to, at such an angle that as the wheel revolves and advances they descend edgewise with the least practical resistance and come up fiatwise, bringing up the earth from the bottom of the cut. Theinclination of the knives and the efi'ect oftheir position are shown in Fig. 2, in which the lines 0 19 show the direction of the plane of the knives. The length of these knives is just equal to the space between the colters a a, whereby they cut up all the earth that the machine passes over. The size of these knives, both as to length-that is, in lateral projection-and width, will be as great as the strength of the material will allow without requiring too great thickness. The width should be about one-fourth the length-that is, equal to about one-half the lateral projection. The outer corners of the knife are rounded off, or the outer edge falling back from the center, in order that hard obstacles, like small stones,

may be pressed aside. The knives are inserted and made fast by means of groove and key or any other mechanical device, so that if one breaks it may be conveniently replaced. The proper position of the knives is theoretically (and the best practical inclination can not vary much from that) the plane of the knife inclined to the radius at an angle of about thirty-seven degrees. This inclination is found practically by describing a circle from the center of the colter or wheel fivetwelfths as large as the whole plate. A line drawn tangent to this circle gives the direction sought. This is represented in Fig 2.

The whole frame is attached to a carriage either of a single set of wheels or of three wheels, whereby it is raised from the ground by means oflevers or other mechanical devices. Various ways of doing this are already common property, and constitute not a part of this invention.

In light soils not cumbered with sods, clods, or weeds, or other such obstacles, the first axle or set of colters may be dispensed with.

The number of colters or wheels may be increased to any extent, limited only by convenience or the capacity of the motive power.

When themachine is enlarged to some width each colter or wheel may have its separate mandrel or axle, and have a certain play up and down under a certain pressure of a weight or spring, whereby they will severally adjust themselves to the the unevenness of surface or yield to any solid obstruction without elevating the whole frame.

I do not claim as such disks or rotary rollers sharpened at their periphery, nor disks having transverse knives on their periphery; but

What I claim is- A system of sharpened disks or rotarycolters, a part of which are armed upon their periphery with knives projecting laterally, said knives being set obliquely to the radius of the disk, as above described, the whole being combined or arranged in three several sets, so that the two sets armed with knives shall cut alternate sections of the soil, substantially as above set forth.

H. M. JOHNSON. Witnesses:

CHAS. E. BLUMENTHAL, SAML. D. KILLMAN. 

